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YOUNG, YOUNG 8t GENGINEERS. GEOLOGISTS
MINING CONSULTANTS42A12SE0284 63.161 ROBB 010
M. I. YOUNG
PAUL VOUNO
W. H. OROIS
TELEPHONE PLAZA 8909
Report on the
Geophysical and Geological Surveys
of the Property of Walcoro Porcupine Mines Ltd.
Robb Township, Porcupine Area, Ontario.
77 YORK STREET TORONTO. ONT.
^ ^CONCLUSIONS
The object of the survey was to investigate the
economic possibilities of the property. Over three quarters
of the property is covered by deep drift and swamp. For this
reason a Magnetic geophysical survey was undertaken in order
to indicate rock contacts and structures and to act as an aid
to the geological work.
The property is believed to be underlain principally
by gabbro. Two types of gabbro occur; one gives high magnetic
readings, the other gives low values. A quartz vein contain
ing low gold values occurs in the gabbro of low magnetic
property. The magnetic survey indicates that the gabbro of
low magnetic susceptibility may extend to the western boundary
of the property. The strength of the shearing containing the
vein, the width of the vein itself and the westward continua
tion of the low anomaly of the vein area strongly suggest that
the vein zones extend to the western boundary of the property.
The logical method of testing the westward extension of the
vein under the overburdened areas is by diamond drilling.
Although gold values have been low where the vein has previously
been exposed by surface trenching and diamond drilling, appro
ximately 2,000 feet of the structure between the most westerly
- 2 -
drill hole and the west boundary of the property has been
untouched and unexplored.
FIELD WORK
Field work for the magnetic survey was started on
May 8 and was completed on May 28th. The geological work
started on May 17th and was completed on May 28th,
PERSONAL
F. Dunn was in charge of the geophysical survey,
W. H. Gross and geologist assistants mapped the geology,
LOCATION AND^^ACCESSIBILITY
The property of Walcoro Porcupine Mines Ltd. is
located in Robb Township, Timmins Mining Division, District
of Cochrane, Ontario, The group consists of twelve claims
whose numbers are P-32852-54. and P-31360 to P-31368 inclusive,
The north-east corner of the group lies one half
mile south-west of Kamiskotia Lake. The township line between
Robb and Turnbull Townships forms the southern boundary of the
property.
The property is roughly 15 miles north-west of
Timmins and can be reached via the Kamiskotia road, A good
trail leads from Jamieson's camp on the Kamiskotia road to the
core shack on the property. The trail is about three miles
long.
LAND ,SJJRVEY
Three base lines were used as a survey control on
this group. The south boundary of Robb Township was used as
- 3 -
the main base line. Two parallel sub-base lines were cut in
the central and northern part of the property. Cross lines
were turned off from the base lines at 300 feet intervals
and they were cut to the limits of the property. These lines
were chained and picketed at 100 feet intervals,
A total of 15 miles of line was cut which included
1,5 miles of base line and 13,5 miles of cross lines.
The line cutting proved to be a major task since
the area covered by the claims is heavily wooded and even the
township line had to be partially recut,
MAPS
Three maps, NOB. W-17, W-18, and W-19, each drawn
to a scale of l inch to 200 feet, accompany this report.
Map No, W-17 shows the magnetic readings in gammas
at each station where an observation was made,
Map No, W-18 shows our interpretation of the magne
tic results and is based on a correlation of the isomagnetic
lines and the geological data,
Map No. W-19 is a geological map of the Walcoro
group as well as pertinent geology from surrounding groups,
TOPOGRAPHY
The Walcoro ground is generally low and swampy with
the exception of Kamiskotia hill in the north-western part of
the property. The hil] rises some 250' to 300' above the
general level. On the southern part of the hill a tail of
sand, gravel, and boulders forms an esker-like ridge which
stretches to the southern boundary of the property.
GENERAL GEOLOGY
Most of the rock outcrops on the property occur in
the vicinity of Kamiskotia hill. The rock is medium to coarse-
grained, of basic composition, and was classified as gabbro
in the field. Irregular bands and patches of gabbro pegmatite
consisting of coarse crystals of feldspar, hornblende, and
magnetite occur in places in the finer-grained gabbro. Small
granite dikes up to 10" wide with strikes of N. 5O E. and
N. 300-400 W. cut the basic rocks. Part of the gabbro is well
banded in a north-west direction. Small shears, 2' to 3' wide,
strike roughly parallel to this banding.
In the south-west corner of the property a medium
to fine-grained acidic rock outcrops. It is possible that
this rock is a rhyolite flow. However, no flow structures
could be identified in the rock and it is therefore more likely
to be an acid intrusive. This rock is cut by northerly tren
ding diabase and smaller basic dikes,
A granite stock outcrops to the east of the property.
Its contacts with the gabbro are shown on the accompanying
Map W-19.
The main showing lies in the south central part of
Claim 31360. It consists of a quartz-carbonate vein cutting
the gabbro country rock. The vein strikes N. 7QP-75O S . and
dips from 35O to 45O to the north. The vein varies in width
from two to three feet and is exposed in two trenches over a
strike length of roughly 200 !. Sulphides, including pyrite,
pyrrhotite and chalcopyrite make up about 1# of the vein.
- 5 -
The vein lies in a shear zone which is up to 20' wide. The
shear strikes parallel to the vein but dips 55O to 60O to the
north.
The vein has been explored for about 1,000* along
the strike by diamond drilling. The location of drill holes
and sample sections where available are plotted on Map W-19.
Much of the core was relogged but all the vein material was
missing as apparently the core was not split when samples were
taken. The gabbro was checked for sulphide mineralization.
One representative five-foot section containing up to 1#
pyrrhotite was assayed for nickel but none was found to be
present.
Cross sections were made through Drill Holes 9A,
10A, 11A, and 12A to check the drill results with the surface
structure. In several drill holes more than one quartz vein
occurred but generally speaking the main intersections of
quartz in the drill holes lined up with the surface dip of the
vein. Assay resmlts from the section of the vein were too
low to be of economic value. However, the vein structure, as
indicated by the width of quartz intersected in the deeper
holes, appears to be fairly strong and continuous and it is
possible that ore shoots may occur in the vein further to the
west.
The gabbro outcrops oh Kamiskotia hill were care-* *
fully inspected for the presence of sulphides, A small amount
of pyrite, believed to be primary, was found disseminated in
the rock. Some hydrothermal pyrite associated with quartz
and carbonate was found in two old pits whose location is shown
- 6 -
on Map W- 19. The mineralization extended over an area only
about ten feet square and thus does not appear to be of
economic interest.
GEOPHYSICAL SURVEY
General
Two magnetometers were used to make the magnetic
observations on the property. One instrument was a Sharp,
one-man, Schmidt-type magnetometer set to a sensitivity of
18.3 gammas per scale divisionj the other was a Schraidt-type
magnetometer set to a sensitivity of 17.5 gammas per scale
division. Base stations were established on the three base
lines and corrections were made for diurnal variation, temper
ature changes, and possible changes in the centres of gravity
of the instruments due to shock. With the above corrections
applied to the field readings the magnetic values at each sta
tion stand in absolute relation to one another as though all
of the readings had been taken simultaneously. The number of
magnetic observations taken include 711 at surveyed stations
and 2/,. intermediate readings taken where sharp changes in
readings occ\irred.
Our interpretation of the magnetic readings is shown
on Map No. W-17. The normal vertical magnetic intensity of
the rocks on this property was assumed to be between 300 and
1,000 gammas. Areas above 1,000 gammas are coloured blue and
areas below 300 gammas are coloured yellow. Deeper shades of
blue and yellow indicate a greater departure of the magnetic
values from the normal readings,
- 7 -
The area of higher than normal magnetic readings in
the northern part of the property is underlain by gabbroic rocks.
These rocks were examined in some detail and they were found to
contain considerable magnetite. The amount and grain size of
the magnetite was exceedingly variable but in places it makes
up to 10-15^ of the rock. Magnetite has a high magnetic
susceptibility and is believed to have caused the high magnetic
readings over the gabbro in this vicinity.
There is a sharp contrast between the higher than
normal readings in the northern part of the property (coloured
b.1ua on Map No. W-18) and the lower than normal readings
(coloured yellow) adjoining to the south. Outcrops of gabbroic
lookinp rock occur in this yellow coloured area. Here, however,
the gabbro is generally altered and has a low magnetite content.
The reason for this alteration and reduction in the magnetite
content is in doubt. It may be attributed to metamorphism
caused by the large scale intrusion of granite, differentiation
in the gabbro intrustion, or possibly two separate intrusions
of gabbro one of which has a high content of magnetite. In
order to differentiate between gabbro giving high and those
giving low magnetic effects the outcrops are lettered 2 and 2A
respectively,i
Tt may be significant that the quartz vein of the
main showing lies in this low magnetic area. It is also note
worthy that the quartz vein is closely overlain by a much lower
than normal magnetic area which is closely parallel to the
strike of the vein. The area of low anomaly extends westward
across the property. The most westerly drill hole gave a good
- 8 -
width in quartz although the gold values were low. (Refer to
Map No. W-19). Nevertheless, the drilling indicates a vein
of good width, and shearing on the surface is quite strong,
Furthermore, the geophysical survey suggests that the struc
ture extends to the western boundary of the property. This
would open up approximately 2,000' of favourable prospecting
ground beceuse although in general low gold values have been
obtained from the vein to date, it is possible that ore shoots
may occur on the westward extension of the vein,
The northerly trending anomaly in the south-west
part of the property is caused by a diabase dike which is
shown on the geological Map No. W-19. Detailed magnetic work
showed that the dike gave higher than normal magnetic readings.
Contacts of the diabase were checked for radioactivity with a
Geiger counter. No activity above normal was noted,
The higher than normal readings in the south-east
part of the property is considered to be the manifestation of
the granite contact which closely parallels the anomaly.
RECpjMENDATIONS
The surveys were successful in indicating the west
ward continuation of the known shear zone and quartz vein and
in indicating probable geological conditions under overburdened
portions of the property. Although there were practically no
oxitcrops except in the northern portion of the property, the
magnetic survey indicates that the overburdened areas are
underlain by gabbro of low magnetic susceptibility.
Future exploration possibilities on the property
appear to be confined to the unexpDored portion of the known
. Q .
quart?, vein. Approximately 2,000' of this structure, along
strike, SB indicated by the magnetometer survey, is covered
by overburrlftn end has not been explored by diamond drill
holes. The strength and persistence of the vein structure,
and the fact that low gold values are present, appear to just
ify a modest amount of exploratory diamond drilling between
Diamond Drill Hole No, 19A and the western boundary.
Respectfully submitted,
YOUNG, YOUNG b GROSS, LIMITED
Perj W, H, Gross, P, Eng,
Toronto, June 1949
Encs. Maps Nos. W-17, W-18, W-19.
M.E.VOUNO
PAUL; YOUNG W. H.JOROSS
YOUNG, YOUNG B GROSS, LIMITEDENGINEERS, GEOLOGISTS a OEOPHYSICISTS
MINING CONSULTANTS-EXPLORATION
TELEPHONE PLAZA 59O9
77 YORK STREETTORONTO, ONT.
The following statement, which is certified to be
correct by the undersigned, is fo form an appendix to the Report
on The Geophysical and Geological Surveys of the Property of
Walcoro Porcupine Mines Ltd,, Robb Township, Timmins Mining
Division, District of Cochrane, Ontario, by Young, Young St Gross,
Limited, dated June l5th, 19k9.
l* Name of Firm
2. Dates of Field Work
3* Types of instruments, and Scale Constant
it* Total number of Stations established
5* Number of miles of line cut
6. Maps
7. Report
8* Breakdown of man-days employed
(A) Geophysical
Young, Young Se. Gross, Limited
Geophysical-May 8th~28th, 19h9 Geological -May l?th-28th, 191*9
2 Schmidt-type Magnetometers 18*3 and 17*5" gammas per scale division
l?
W-17, W-18, TIHL9, submitted
June 19^9, submitted
(a) Line-cuttersArchibald Henley, Timmins - May 8-26 - 19 days x I; George Demeria, Timmins - May 8-26 - 19 days x h
(b) Instrument Operators F. S* Dunn - May 8-28 - 21 days x
7676
81W.H*Gross helped by Milne - May 8-16 - 18 days x li 72
(cont'd)
YOUNG, YOUNG a GROSS. LIMITED
(B) Geological
(a) Field WorkW.H.Gross, K.Morgan,I.Milne- Mayl?~28
(C) Office
(a) DraftingA. B. Ferguson
(b) Consultants (report, etc.) -
- 33 days x li 132 15-
6 days x it 2li
6 days x h 2k
TOTAL OF MAY-DAYS3 T-
Ge+t
YOUNG, YOUNG ft GROSS, LIMITED,
Perj W. H. Gross,Professional Engineeri
"9
. '. MIAU MMNETITE *. * ' CONCENTRATIONS
-..--. .'-. \ ...-..'l'- . \
P-32852
P-32853
..-" vv . FINE- TO MEDIUM-GRAINED \'.\ GRANITIC ROCK
LOW GROUND
HEAVY OVERBURDEN
\P-32854 P-3I36I P-31360
\ H
Fine-grained basic dike
Medium to fine-grained siliceous roc* ; may be intrusive
P-31362Medium to fine-grained granitic
Gabbro, medium to coarse-grained2a : gabbro, exceedingly variable texture
LOW GROUNb
[^ ^ l Swamp
Topographic boundary
Boundary of rock outcrop
Geological boundary
Assumed geological boundary
Assays in ounces gold X widths in feet
Strike 9 dip of schistosity
Strike a dip of fracturingSUB BASE L INE
P-31363
P-31366P-31365P-31367P-31369
ROBB TWP. TURNBULL TWR
PORCUPINE MINES, LTD.WALCOROROBB TOWNSHIP DISTRICT OF COCHRANE
GEOLOGICAL PLAN
SCALE : Ir 200' DATE -- J UNE , 1949
MAP NO YOUNG, YOUNG B GROSS, LTD
\
rsi^, ,6000T
SUB BASE LONE
ROBB TWP.TURNBULL TWP.
NORMAL INTENSITY
ABOVE NORMAL I NTENSITY
BELOW N ORMAL INTENSITY
WALCORO PORCUPINE MINES , LTD.
ROBB TOWNSHIP DISTRICT OF COCHRANE
MAGNETIC CONTOURS
SCALE l" - 300'
O 50 i 00 200 400 600
DATE -- J UNE . 1949
600
MAP NO YOUNG, YOUNG 8 GROSS,LTD.
N
o c
P-32853 P-32852
SUB BASE L INE
P-31360
4500 N
P-3I36IP-32854
P-31362
SUB B ASE T L INE
P-31363fc^-a.
P-31366P-31369 P-31367
ROBB TWPTURNBULL TWP.
WALCORO PORCUPINE MINES , LTD.
ROBB TOWNSHIP DISTRICT OF COCHRANE
MAGNETIC READINGS
SCALE '- l " * 200' DATE ' J UNE , 1949
O 50 100 200 400 600 800
MAP NO. YOUNG, YOUNG Q GROSS.LTD
220